CVEvulnerability

CVE-2021-30666

8.8 HIGH Known exploited Published 2021-09-08 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Apple iOS WebKit Buffer Overflow Vulnerability — Apple iOS

Apple iOS WebKit contains a buffer-overflow vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.

Added to KEV
2021-11-03
Remediation due
2021-11-17
Ransomware use
Unknown
Required action
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-30666
Status
Analyzed
Published
2021-09-08
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected])
6.8 MEDIUM — AV:N/AC:M/Au:N/C:P/I:P/A:P
Weaknesses
CWE-119

Description

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.5.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

Affected configurations

• apple iphone os (< 12.5.3)

Related

Weakness · CWE (1)

  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer weakness

References